The storage and use of the grease - bearing knowledge
The storage and use of the grease - bearing knowledge
Grease storage of the different varieties of many, the performance of the grease and fat more easily than oil metamorphism, and fat with impurity is not easy to handle, so significant importance to strengthen quality management in grease storage.
1, quality change in grease storage grease after long-term storage quality changes in the following aspects: 1)
A color change;
In contrast, dust and other mechanical impurities;
Mixed with water or absorb water: 4)
After long-term storage of lubricating oil, formed a lump, oil soap, generate acid, corrosion unqualified, etc.
2, storage in the cause of grease deterioration in grease storage deterioration reasons include: external introduction of impurities and moisture.
Physical or chemical change in the grease itself.
3, 1) delay the measures of grease stored in metamorphic
Grease priority put in storage, reduce the influence of temperature, moisture, dust, etc;
Lower storage temperature;
According to the characteristics of different kinds of grease, enhance the management of the targeted;
Pay attention to seal storage;
Pay attention to take fat tools, container cleaning;
For different users, the use of large, medium and small different packing form;
Pay attention to inventory the regular tests of the grease.
The major form of failure: 1, the oxidation of 2, grease colloid structure damage 3, 4, grease oil and base oil play lost 5, foreign bodies, with 6, grease aging (
Sclerosis, loss of lubrication)
Comply with the following one, that is, to failure: 1, the consistency of change, achieve + / - (
15 ~ 20)
%, generally need to change fat;
2, drop point changes, the soap base grease, which of the following sentences is aging failure: lithium base grease under 140 ℃, sodium based fat calcium base grease under 120 ℃ to 50 ℃ below, composite aluminum compound lithium under 180 ℃ 200 ℃ below, other, more than plus or minus 20% 3, acid value changes grease acid value & gt;
3 mgkoh/g failure 4, namely mechanical impurity content, the following Fe> for failure;
1% or Cu>
3% or ash content rate & gt;
Grease failure resolution (
Physical factors of failure in use at the same time they have been subjected to mechanical shear grease and grease under the action of centrifugal force will be left out of the friction interface and the oil, decrease oil grease, with the decrease of the cone into the degree of hardening, to a certain degree of grease will complete failure;
Under the effect of mechanical shear, the structure is damaged (grease
Such as soap fiber release or orientation)
, cause its softening, consistency and analysis such as oil, eventually lead to failure.
Usually, use grease transfer speed 2000 r/min, half will reduce its life.
Under high shear stress, the double speed, service life is only equivalent to 1/10 of the original life.
Chemical factors caused by the failure of grease acid react with the oxygen in air to produce, it first is an antioxidant additive, the consumption of fat, but to a certain extent, generated by the organic acid corrosion of metal components and destroying the structure of fat, make its drop point drop, such as base oil viscosity increase and liquidity.
A large number of tests show that the higher the temperature, the more obvious drop in the life of the grease.
Such as temperature at 90 ~ 100 degrees, the temperature rise every 19 degrees, the service life of grease by about half, in 10 ~ 150 degrees, the temperature rise every 15 degrees, the service life of grease will be fallen by half.
In addition, the grease of moisture, dust and harmful gases, such as using environment and make its degradation is one of the important factors.
For example: fat in copper, iron, lead, and bronze wear particles, such as on the lipid oxidation catalytic role.
In short, the failure of the grease for many reasons, and sometimes can be caused by a reason, but more is the result of multiple factors the same role, or in a reason as the breakthrough point, and then other reasons work together.
The correct use of the grease (
Amount of lubrication filling to be appropriate and large amount of fat, can make the friction torque increase, temperature, increase of fat consumption;
And fatliquoring quantity too little, cannot obtain reliable and smooth and dry friction.
Generally speaking, appropriate amount of fatliquoring for bearing inner 1/3 ~ 1/2 total void volume.
But according to situation, sometimes it is should be on the edge of the bearing with grease and cavity lubrication.
Pay attention to prevent the mixture of different kinds, grades and the old and new grease to avoid fat container and tool use, otherwise, will have a drop point down on fat, cone into the degree increased and mechanical stability etc.
Attaches great importance to the new grease work by Yu Run fat varieties, quality is in constant improvement and change, the old equipment to switch to the new grease, should look after the test, trial rear can officially use;
When change the new fat, should first remove waste grease, clean parts clean.
When adding grease, waste should be fat extrusion, when fat mouth see new grease.
Attaches great importance to the process of filling grease in the management before receiving and filling grease, must strict attention to containers and tools clean, equipment for fat mouth should be wiped clean, protected from mechanical impurity, mixed with dust and sand.
Pay attention to the season with fat timely replacement such as equipment environment in winter and Xia Li and change of temperature difference is bigger, if summer of fat in the winter, or on the contrary, the result will be counter-productive.
Note plus in grease grease and regularly in time should be used according to specific circumstances, to ensure the reliable lubrication and not cause fat waste.
Don't use wooden or paper packaging harden, mixed with water to prevent loss of oil or grease contamination, and should be stored in a cool and dry place.